There is a pressing need for an engine that will use less fuel and yet provide the same or more propulsive force. Balanced with the need for increased efficiency is an environmental need for less pollutants. These objectives are ever-increasing.
Many inventions, modifications or improvements have addressed themselves to these needs. Exemplary of fuel efficiency is U.S. Pat. No. 4,163,436 to Fugett which provides a greatly improved manner for causing gas to be more completely burned. There have been efforts to modify the style of the engine itself by reducing the power of the engine, or the size of or configuration of the cylinders, per se, or the method for injecting the fuel into the cylinder.
Recent publicity discloses the elimination of spark plus and other gasoline engine parts to provide an engine that operates entirely from compressed air. Such a system is limited in that its fuel, compressed air, is expendable. There is a limited range in which such a vehicle can operate without running out of fuel. In this regard it is very similar to the battery powered motors.
The compressed air tank must be filled with compressed air while the car is at home or while it is at a place where compressed air may be obtained. An engine operated from only compressed air is thus limited in that the distance within which it is limited to is a relatively confided area.